I use Fancy Feast but haven't noticed any problems with it but now I'll be checking more carefully.There are other grain free canned cat foods out there if you can find one that they like.
Cats should only be fed frain free wet food.I also went through the Diabetes with one of my guys,8 months of out of control blood sugars 3 different insulins...within 3 weeks of getting him off dry food his Diabetes was in remission.
Cats are true carnivores and they require protein to get all there nutrients and can't properly digest corn,wheat,rice or barley and that's what dry food is made of-mostly.
I know I do go on a bit about the food but after Melle's experience I did a lot of reading and I now try to encourage folk to get their cats off the dry